​Tolo Lake, near Grangeville, was in the news in the fall of 1994 when the Idaho Department of Fish and Game was deepening the drained lake to provide for better fishing. Fish and Game was hoping to take out a dozen feet of silt so that it could better support fish and waterfowl. What they found during the excavation was neither fish nor fowl. It was something much, much larger.

Tolo Lake, which is about 36 acres, was a rendezvous point for the Nez Perce, or nimí·pu, for many years, including at the start of what became the Nez Perce War. Digging there could help wildlife, sure, but it could also shed light on the Tribe’s history. But when the first bone was exposed it was clearly not an artifact of the Nez Perce occupation of the site. It was a leg bone 4 ½ feet tall. Its discovery quickly piqued the interest of archeologists, so scientists from the Nez Perce National Forest, Idaho State Historical Society, University of Idaho, and the Idaho Natural History Museum descended on the site where it was quickly determined that these were the bones of mammoths.

Mammoths were not called that for nothing. They weighed 10-15,000 pounds and stood about 14 feet at the shoulder. They were alive in North America as recently as 4,500 to 12,500 years ago, meaning they may have been familiar to the first people on the continent.

The dig exposed the bones of three mammoths and an ancient bison skull. The longest tusk discovered was measured at 16 feet. One of the tusks is on display at the Bicentennial Museum in Grangeville. The town also boasts a mammoth skeleton replica in an interpretive exhibit next to the Grangeville Chamber of Commerce office.

Tolo Lake, which was listed on the National Register of Historic Places in 2011, was named for a Nez Perce woman who alerted settlers of the rampage that started the Nez Perce War.